1. Field of the Invention
The present invention relates to a therapeutic silicone gel composition formulated for topical application for the treatment of hypertrophic conditions of the skin such as keloids.
2. Prior Art
Keloid and hypertrophic scars appear on the skin after injury or acne which usually causes much distress, both aesthetic and functional, to the patient and can become a lifelong problem unless medically treated. Silicone gel or a gel-coated occlusive sheeting is widely used for the treatment of hypertrophic and keloid scars, though at present there is no scientific explanation as to its mode of action. With silicone gel treatment, softening and flattening of scars is observed after months of continuously covering of the scar with a layer of the silicone gel.
The skin and the dermis of hypertrophic and keloid scars are histologically and chemically different from that of intact skin. In the epidermis of these scars the keratin layer is thin or even absent, while in intact skin, keratin forms an insulating layer. Due to the extended period of time required to produce a therapeutic result, it is an object of the present invention to provide a “dry” silicone gel composition that can be applied directly to the effected skin without the need for an occlusive dressing; the composition being operable for the non-invasive treatment of hypertrophic and keloid scars. There is a further need for a dispenser for the “dry” therapeutic silicone gel composition which renders the composition easy to self-administer.
There have been many prior art attempts to provide a wound covering that reduces excessive scarring during the healing process. U.S. Pat. No. 4,725,279 discloses a biocompatible material for a thermal burn dressing. The material is a composite comprising a thin film of thermoplastic material such as Silastic. U.S. Pat. No. 4,838,253 discloses a liquid permeable dressing comprising one or more sheets of apertured material, such as cotton gauze, coated with a tacky silicone gel or a non-tacky silicone elastomer. U.S. Pat. No. 5,395,305 discloses a wound-covering material comprising two layers: a first support layer which is in contact with the wound and which contains a water-repellant substance and a second moisture permeation controlling layer which may be formed from permeable resin films made of silicone or polyurethane elastomers. U.S. Pat. No. 5,196,190 discloses a membrane suitable for wound dressing comprising a natural or synthetic polymer, a non-gellable polysaccharide and a cross-linking agent. U.S. Pat. No. 3,803,300 discloses an ointment foil for application to skin. The ointment foil is prepared by drying an oil-in-water emulsion of ointment ingredients to a moisture content of 1% to 15%. U.S. Pat. No. 3,867,520 discloses a medicated polyamino acid film for occlusive dressing therapy.
Notwithstanding the advances made in prior art wound dressings for the reduction of scar formation, there remains a need for compositions and devices for administering the compositions which are operable for reducing the profile of a scar after the wound has healed and the scar has already formed. Silicone gel is known to reduce the profile of scars but in accordance with the prior art, silicone gel is held in contact with the scar by an occlusive dressing which is unsightly and inconvenient to use. Accordingly, there is an ongoing need for a silicone gel composition operable for the non-invasive treatment of hypertrophic and keloid scars and a dispenser for the therapeutic silicone gel composition which renders the composition easy to self-administer.